How severe is CVE-2020-1147?

CVE-2020-1147 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-1147?

CVE-2020-1147 affects the following packages: Microsoft.NETCore.App (NuGet), Microsoft.NETCore.App.Runtime.linux-arm (NuGet), Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet), Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet), Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet), Microsoft.NETCore.App.Runtime.linux-x64 (NuGet), Microsoft.NETCore.App.Runtime.osx-x64 (NuGet), Microsoft.NETCore.App.Runtime.rhel.6-x64 (NuGet), and 4 more. Ecosystems affected: NuGet.

How do I fix CVE-2020-1147?

Update Microsoft.NETCore.App to 2.1.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1147 is resolved across your whole dependency graph.

How do I detect CVE-2020-1147 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.NETCore.App, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-1147 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2020-1147 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2020-1147, including 2 documented proof-of-concept exploits on Exploit-DB and 6 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-1147?

CVE-2020-1147 has an EPSS (Exploit Prediction Scoring System) score of 94.0%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2020-1147 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-1147 (Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2020-1147 published, and has it been updated?

CVE-2020-1147 was published on July 14, 2020 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2020-1147 — Microsoft.NETCore.App

HIGH

CVE-2020-1147 is a high-severity (CVSS 7.8) remote code execution vulnerability in Microsoft.NETCore.App. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. A fix is available for Microsoft.NETCore.App — see the affected versions and patch details below.

.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability

Also known asGHSA-g5vf-38cp-4px9

Published

Jul 14, 2020

Updated

Oct 20, 2026

Affected

12 pkgs

Patched

12 / 12

Exploits

8 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2020-1147.

EPSS Exploitation Probability

via FIRST.org ↗

94.0%probability of exploitation in next 30 days

Very High Risk0.00%

Lower risk than most CVEs100th percentile — riskier than 100% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-1147 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).

Where this sits among everything scored

Of 394,415 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

12 pkgs affected

.NETMicrosoft.NETCore.App.NETMicrosoft.NETCore.App.Runtime.linux-arm.NETMicrosoft.NETCore.App.Runtime.linux-arm64.NETMicrosoft.NETCore.App.Runtime.linux-musl-arm64.NETMicrosoft.NETCore.App.Runtime.linux-musl-x64.NETMicrosoft.NETCore.App.Runtime.linux-x64.NETMicrosoft.NETCore.App.Runtime.osx-x64.NETMicrosoft.NETCore.App.Runtime.rhel.6-x64+4 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability'.

Affected Packages

12 total 12 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.NETCore.App`	≥ 2.1.0&&< 2.1.20	2.1.20`dotnet add package Microsoft.NETCore.App --version 2.1.20`
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-arm`	≥ 3.1.0&&< 3.1.6	3.1.6`dotnet add package Microsoft.NETCore.App.Runtime.linux-arm --version 3.1.6`
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-arm64`	≥ 3.1.0&&< 3.1.6	3.1.6`dotnet add package Microsoft.NETCore.App.Runtime.linux-arm64 --version 3.1.6`
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-musl-arm64`	≥ 3.1.0&&< 3.1.6	3.1.6`dotnet add package Microsoft.NETCore.App.Runtime.linux-musl-arm64 --version 3.1.6`
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-musl-x64`	≥ 3.1.0&&< 3.1.6	3.1.6`dotnet add package Microsoft.NETCore.App.Runtime.linux-musl-x64 --version 3.1.6`
.NETNuGet	`Microsoft.NETCore.App.Runtime.linux-x64`	≥ 3.1.0&&< 3.1.6	3.1.6`dotnet add package Microsoft.NETCore.App.Runtime.linux-x64 --version 3.1.6`

Affected Products

6 products · 41 configurations

Application

.net coremicrosoft

2 versions

2.13.1

Application

.net frameworkmicrosoft

12 versions

2.03.03.53.5.14.5.24.64.6.14.6.24.74.7.14.7.24.8

Application

sharepoint enterprise servermicrosoft

2 versions

20132016

Application

sharepoint servermicrosoft

2 versions

20102019

Application

visual studio 2017microsoft

≥ 15.0 && ≤ 15.9

range

Application

visual studio 2019microsoft

≥ 16.0 && ≤ 16.6

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-50151webappsaspx

Microsoft SharePoint Server 2019 - Remote Code Execution (2)

by Podalirius · Jul 23, 2021

Exploit-DB Source

EDB-48747webappsaspx

Microsoft SharePoint Server 2019 - Remote Code Execution

by West Shepherd · Aug 17, 2020

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.NETCore.App, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.NETCore.App to 2.1.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1147 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatCritical

Product	Fixed in	Advisory
.NET Core on Red Hat Enterprise Linux	`rh-dotnet21-0:2.1-19.el7`	RHSA-2020:2937
.NET Core on Red Hat Enterprise Linux	`rh-dotnet31-dotnet-0:3.1.106-1.el7`	RHSA-2020:2939
Red Hat Enterprise Linux 8	`dotnet-0:2.1.516-1.el8_2`	RHSA-2020:2938
Red Hat Enterprise Linux 8	`dotnet3.1-0:3.1.106-1.el8_2`	RHSA-2020:2954
Red Hat Enterprise Linux 8.0 Update Services for SAP Solutions	`dotnet-0:2.1.516-1.el8_0`	RHSA-2020:2989
Red Hat Enterprise Linux 8.1 Extended Update Support	`dotnet-0:2.1.516-1.el8_1`	RHSA-2020:2988

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-1147 in your dependencies?

Find it across NuGet, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

7.8/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jul 14, 2020

First exploit

Jul 23, 2021

KEV added

Nov 3, 2021

Last updated

Oct 20, 2026

Identifiers

CVE-2020-1147

GHSA-g5vf-38cp-4px9

References

Advisorynvd.nist.gov Fixportal.msrc.microsoft.com Webcisa.gov Webgithub.com Evidencepacketstormsecurity.com Evidencepacketstormsecurity.com Evidencepacketstormsecurity.com Evidenceexploitalert.com

Related vulnerabilities

This CVE is high severity; 4 of 8 other CVEs affecting Microsoft.NETCore.App are rated as high or higher (top: high).

CVE-2021-34485CVE-2021-1721CVE-2020-1108CVE-2017-8585CVE-2019-0545CVE-2019-0564CVE-2019-0657CVE-2018-8416

Provenance

Sources

OSV.devNVDCISA KEVFIRST.org (EPSS)

Last verifiedOct 20, 2026

CVE-2020-1147 — Microsoft.NETCore.App

Exploitation Status

Actively exploited in the wild

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2020-1147 in your dependencies?